The goal of this laboratory program of our NCNPDDG project is to obtain leads for anticancer drugs from marine sponges and their symbionts. Special attention will be given to: Indo-Pacific and Caribbean sponges from taxonomic families that have not been well studied, sponges that are rich in cyanobacteria and cultured actinomycetes that can be separated from sponges. The collaborating Pharmaceutical group at Sandoz will provide the assay work on our samples. Specific aims of this laboratory are: (a) To continue the exploration of tropical sponges for novel active compounds. (b)To examine the potential of marine actinomycetes (especially those separated from marine sponges) for novel active compounds. (c) To continue the study of sponges with cyanobacterial symbionts. (d) To employ mechanism-dependent assays for selection of extracts with activity against newly discovered and clinically important molecular targets. (e) To efficiently isolate secondary metabolites from active crude extracts guided by high throughput screens. (f) To complete the total structure elucidation of active compounds. (g)To initiate scale-up reisolation by recollection of macroorganism or reculture of macro organisms of actives whose novel structure and promising bioactivity dictate their further study in the secondary screens. A multistage process will be used to obtain lead compounds. it begins by collecting annually, more than 200 new Indo-Pacific or Caribbean sponges for further extraction. About 100 marine actinomycetes will also be grown in culture each year. These will be obtained exclusively from the tissue of tropical sponges. The extracts of these macroorganisms and microorganism will be evaluated in primary screens which seek: signal transduction inhibitors of the SH2 domain containing proteins; inhibitors of nuclear transcription factors; reversal of transformation agents; or drugs relevant to apoptosis. Active extracts will be subjected to a cycle of bioassay-directed solvent partitioning and then chromatographic purification. The structures of the actives will be established by powerful spectroscopic tools headed by two-dimensional nuclear magnetic resonance. Another source for primary screen leads will be the 1,000 sponges and over 500 compounds in our repository. Primary screen active compounds will be further studied for their potency, breadth of activity, and in vivo efficacy. Overall, we believe this approach will lead to the discovery of new compounds active against important solid tumor cancers including breast, colon, lung, ovarian and prostate.